Thursday, May 30, 2019 – Collecting water samples before transiting southward
PUPCYCLE Log – Day 07: The Bubble Lab
We started the day offshore and southwest of the Oregon–California state line collecting more water samples from a broad shelf region of the California Upwelling Zone. Each research group uses a variety of methods for collecting their water samples, based on the organisms or
The scientists studying trace metals and dissolved particulates use different equipment to collect their water samples. Claire Till (Humboldt State University) is investigating 13 trace metals found in seawater. Seven of these are micronutrients used by marine organisms and include: Iron (Fe), Manganese (Mn), Copper (Cu), Cobalt (Co), Cadmium (Cd), Nickel (Ni), and Zinc (Zn).The additional six trace metals are not micronutrients in the aquatic food web but can provide insights into other oceanic processes, such as scavenging, where dissolved elements attach to other dissolved particles before sinking. These include: Lead (Pb), Gallium (Ga), Cerium (Ce), Yttrium (Y), Lanthanum (La), and Scandium (Sc). Claire noted that much remains to be learned about the trace metals adding, “Scandium is chemically similar to iron but is not a nutrient.” She suspects that Scandium might act as a substitute for iron, causing interference in the iron uptake by diatoms and other phytoplankton. Claire is hoping to learn more about Scandium during PUPCYCLE 2019 to see if this type of relationship exists.
Since many of the metals they study are also found in the ship and shipboard materials, the scientists use specially designed equipment, including a Teflon-coated GoFlo® system to keep these metal contaminants away from their samples. The GoFlo® system is designed to collect water through a GoFlo® bottle (similar to the CTD Niskin bottle) attached to a nonmetal line and lowered into the water column. Once the selected depth has been reached, a signal is activated for the GoFlo® bottle to close and capture the water. However, rather than receive an electrical signal from a computer through wiring on the ship, the bottle is
Claire Till was born in Newton, MA and received her undergraduate degree in Chemistry from Bates College (Lewiston, ME). She completed her PhD at the University of California – Santa Cruz in Ocean Sciences and is currently at Humboldt State University.